Liquid spraying apparatus

ABSTRACT

Liquid spraying apparatus especially, but not exclusively for use in paint spraying operations, the apparatus comprising a conduit which has at one end a piston reciprocable by poweroperated means and which is connected at its other end to a diaphragm pump, said pump being actuable by pressure applied to a column of liquid in said conduit by said piston, the diaphragm having a liquid inlet which is disposed adjacent to the pump and having an outlet which is connected to one end of a further conduit adapted at its other end to be connected to a spray gun.

[75] Inventor:

United States Patent [191 Guise 1 LIQUID SPRAYI NG APPARATUS Frank Guise, Tamworth, England [73] Assignee: Binks-Bullows Limited, Brownhills,

Staffordshire, England [22] Filed: Aug. 4, 1972 [2]] Appl. No.: 278,051

[30] Foreign Application Priority Data Aug. 6, 1971 Great Britain 37,030/71 [52] US. Cl 239/332, 222/385, 417/395, 417/506 [51] Int. Cl B051) 9/04 [58] Field of Search..... 239/332; 222/385; 417/395, 417/506, 435, 901, 388

[56] References Cited UNITED STATES PATENTS 3,623,661 11/1971 Wagner 239/332 [451 Jan. 29, 1974 3/1967 Ward 222/385 X 3,31 1,266 3,680,981 8/1972 Wagner 417/395 3,083,648 4/1963 Patman 417/901 Primary Examiner-A11en N. Knowles [5 7] ABSTRACT Liquid spraying apparatus especially, but not exclusively for use in paint spraying operations, the apparatus comprising a conduit which has at one end a piston reciprocable by power-operated means and which is connected at its other end to a diaphragm pump, said pump being actuable by pressure applied to a column of liquid in said conduit by said piston, the diaphragm having a liquid inletwhich is disposed adjacent to the pump and having an outlet which is connected to one end of a further conduit adapted at its other end to be connected to a spray gun.

4 Claims, 2 Drawing Figures PATENTEU 78 5 34 SHEET 1 BF 2 V PATENTEDJANZQW v 3,788,554

SHEET 2 OF 2 IEm as 2952 5| 52a FIGZ.

1 LIQUID SPRAY ING APPARATUS BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to liquid spraying apparatus which is especially (but not exclusively) intended for operated 'means and at the other end a diaphragm pump whereby in use pressure applied to a column of liquid in said conduit by said piston will be transmitted to said diaphragm pump for actuation thereof, said diaphragm pump having a liquid inlet which is disposed adjacent to the pump and being connected to one end of a further conduit adapted at its other end to be connected to a spray gun, the arrangement being such that when the diaphragm pump is immersed in a container containing a liquid to be sprayed, actuation of said pump will result in delivery of such liquid to the spray gun via' said further conduit.

Conveniently, said power-operated means comprise an electric motor which isdisposed above a platform arranged to be placed on top of a container from which liquid such as paint is to be sprayed, the first-mentioned conduit then extending below said platform sothat in the use the diaphragm pump will be disposed adjacent to the bottom of the container.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be more particularly described with reference to the accompanying drawings wherein: q

FIG. 1 is a fragmentary, part-sectional elevational view showing the upper and lower ends of one example of liquid spraying apparatus constructed in accordance with the invention, and

FIG. 2 is a part-sectional elevational view, on a larger scale, of the lower end of-the apparatus seen in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the apparatus shown therein is intended for use in spraying paint although of course it is'to be'understo'od that other liquids can be sprayed by the apparatus as well.

In the example now described there is provided a platform and above this platform is mounted an electric motor 11 of any conventional form which is arranged so that in use its shaft 12 extends in a generally horizontal direction. On one end of the shaft 12 or a shaft extension is mounted an eccentric 13 which operatesQthrough the intermediary of a roller 14, on the upper end of a piston 15 which is itself disposed at the upper end of a conduit 16 in the form of a metal tube. The conduit 16 extends below said platform 10 and the aforementioned eccentric 13 and roller 14 together with said piston 15 are mounted in a fluid tight housing 17 which contains a liquid such as oil, the arrangement being such that the oil also fills the aforementioned conduit 16.

The lower end of said conduit 16 communicates via ports 16a with one side of a diaphragm pump 18 so that reciprocation of said piston 15 by rotation of said eccentric 13 will result in pressure being transmitted through the oil in the conduit 16 and ports 16a to operate the diaphragm pump, return movement of the diaphragm 18a being effected by means of a spring 19 in the known manner. Furthermore, the axis of said diaphragm 18a also extends in a generally horizontal direction.

Adjacent to the upper end of said conduit 16 but below the aforementioned piston 15 is a relief valve 20 which will open to prevent damage being caused to said diaphragm pump 18 if it is desired to stop spraying whilst the electric motor 11 is kept running. Thus lifting of a plunger 21 in said relief valve 20 against spring 22 (the pressure of which can be adjusted by screw 23) consequent upon a rise of pressure in the conduit 16 will serve to return oil from the conduit via passage 24, port 25 and passage 26 to the interior of the housing 17.

In use apparatus asabove-described would be mounted on a suitable container 27 which will contain paint to be sprayed and conveniently said container is arranged so that a small well 28 is provided in its base, the length of the aforementioned conduit 16 in relation to the depth of the container then being such that the diaphragm pump 18 which is connected to the bottom of said conduit will be disposed at least partially in said well.

The diaphragm pump 18 has an inlet valve 29 mounted in a housing 30 having a chamber 31 into which paint or liquid can flow from the well 28 via ports 32 and filter 32a. Said inlet valve 29 is arranged to co-act with a seat 33 formed at one end of said chamber 31 and from that side of the inlet valve remote from the diaphragm pump 18 there projects a stem 34 which extends with clearance through a bore 35 formed in said housing 30. At its outer end the stem 34 is screwed to receive a nut 36 which acts as an adjustable abutment for one end of the spring 37 the other end of which bears against a shoulder 38 formed in the exterior of the housing 30.

In the rest position of said inlet valve 29 and diaphragm pump 18 (as seen in FIG. 2) there is a clearance between the valve and its seat 33. In other words, the spring 37 is adjusted so that in the rest position of the inlet valve 29, the latter will not be completely closed. As soon as the motor 11 is energised however and the diaphragm 18a begins to move towards the inlet valve 29 under pressure of oil transmitted along the conduit 16, any air within the diaphragm pump between the diaphragm and the inlet valve will be expelled past the latter and out of said pump. Furthermore, the aforementioned clearance between said valve stem 34 and bore 35 will enable said stem to become misaligned relative to the axis of the bore 35 so that even when the valve 29 engages its seat 33 there may not be complete gas tight contact and this also assists in the clearance of air from the diaphragm pump. When any such air has been cleared the pump will be primed so that as the diaphragm 18a moves to the right as seen in FIG. 2, paint will be expelled from the pump into a passage 39 and thence past a non-return valve 40 into the lower end of a further conduit 41. Movement of the diaphragm 18a to the left as seen in FIG. 2 by action of the spring 19 (which will have been compressed by diaphragm movement to the right) will of course serve to draw paint into the pump via the filter 32a,

ports 32, and past the inlet valve 29 which will be drawn to the left as seen in FIG. 2, thereby compressing the spring 37 for returning the valve 29.

The upper end of said further conduit 41 is connected to one end of a hose (not shown) to the other end of which a spray gun of any conventional form is fitted. The spray gun would be provided with a trigger control so that an operator using the gun can control the spraying of paint in a normal manner.

With an arrangement as above-described it is found that little or no difficulty arises in priming the pump 18 on starting up and the pump will readily be able to deal with any small amount of air that may have collected in the pump circuit before pumping commences The aforementioned container 27 is conveniently provided with releasable clamps (not shown) which are arranged to clamp said platform 11 in position so that the platform together with electric motor 10, the two conduits 16 and 41, and diaphragm pump 18 can be readily detached when it is desired to move the apparatus into a new container or to replenish the paint supply in the original container.

What is claimed is:

1. Liquid spraying apparatus comprising a conduit having at one end a piston reciprocable by poweroperated means and at the other end a diaphragm pump whereby in use pressure applied to a column of liquid in said conduit by said piston will be transmitted to said diaphragm pump for actuation thereof, said diaphragm pump having a liquid inlet which is disposed adjacent to the pump and being connected to one end of a further conduit adapted at its other end to be connected to a spray gun, said diaphragm pump being provided with a spring-loaded inlet valve having a seat, said inlet valve being positioned when in its rest condition so that a clearance is formed between it and said seat, and having a stem which extends with clearance through a bore formed in an inlet valve housing to permit slight misalignment of said stem relative to the axis of said bore, the arrangement being such that when the diaphragm pump is immersed in a container containing liquid to be sprayed, actuation of said pump will result in delivery of such liquid to the spray gun via said further conduit.

2. Liquid spraying apparatus as claimed in claim 1 in combination with a liquid container wherein there is provided a platform which engages the upper end of said container and wherein said power-operated means comprises an electric motor which is disposed above said platform, said first-mentioned conduit extending below said platform into the container, the length of the first-mentioned conduit relative to the depth of the container being such that said diaphragm pump is disposed adjacent to the bottom of the container.

3. Liquid spraying apparatus as claimed in claim 1 wherein the upper end of said first-mentioned conduit is provided with a spring-loaded relief valve arranged to relieve fluid pressure in said first-mentioned conduit when such pressure exceeds a pre-determined value.

4. Liquid spraying apparatus as claimed in claim 2 wherein the upper end of said first-mentioned conduit is provided with a spring-loaded relief valve arranged to relieve fluid pressure in said first-mentioned conduit when such pressure exceeds a pre-determined value. 

1. Liquid spraying apparatus comprising a conduit having at one end a piston reciprocable by power-operated means and at the other end a diaphragm pump whereby in use pressure applied to a column of liquid in said conduit by said piston will be transmitted to said diaphragm pump for actuation thereof, said diaphragm pump having a liquid inlet which is disposed adjacent to the pump and being connected to one end of a further conduit adapted at its other end to be connected to a spray gun, said diaphragm pump being provided with a spring-loaded inlet valve having a seat, said inlet valve being positioned when in its rest condition so that a clearance is formed between it and said seat, and having a stem which extends with clearance through a bore formed in an inlet valve housing to permit slight misalignment of said stem relative to the axis of said bore, the arrangement being such that when the diaphragm pump is immersed in a container containing liquid to be sprayed, actuation of said pump will result in delivery of such liquid to the spray gun via said further conduit.
 2. Liquid spraying apparatus as claimed in claim 1 in combination with a liquid container wherein there is provided a platform which engages the upper end of said container and wherein said power-operated means comprises an electric motor which is disposed above said platform, said first-mentioned conduit extending below said platform into the container, the length of the first-mentioned conduit relative to the depth of the container being such that said diaphragm pump is disposed adjacent to the bottom of the container.
 3. Liquid spraying apparatus as claimed in claim 1 wherein the upper end of said first-mentioned conduit is provided with a spring-loaded relief valve arranged to relieve fluid pressure in said first-mentioned conduit when such pressure exceeds a pre-determined value.
 4. Liquid spraying apparatus as claimed in claim 2 wherein the upper end of said first-mentioned conduit is provided with a spring-loaded relief valve arranged to relieve fluid pressure in said first-mentioned conduit when such pressure exceeds a pre-determined value. 